Improvement in transposing key-boards



A. D. B. WOLFF.

Transposing Key-Boards.

NCL A42,974. Patented September, 1873.

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/ZMQL UNITED STATES PATENT OFFICE.

AUGUSTE D. B. WOLFF, OF PARIS, FRANCE.

IMPROVEMENT IN TRANSPOSING KEY-BOARDS.

Specification forming part of Letters Patent No. 142,974, dated September 16, 1573; application iled February 27, 1873.

To all whom it may concern:

- Beit known that I, AUGUSTE DESIRE BER- NARD WOLFE, of Paris, France, have invented a Transposing Key-Board, of which the following is a specication:

My invention relates to improvements in transposing key-boards, consisting of a series of keys arranged in relation to each other precisely as those of the key-board of a piano or organ, but capable of being applied to and adjusted laterally over such a key-board, or over the operating levers of a piano or equivalent instrument, so that the key7 in which a piece of music is played. will depend upon the lateral position of the supplementary keys, and not, as heretofore, upon the ability of the performer to depart from the order in which the music is written, otherwise called "transposing."

The drawing represents one form of my transposing instrument, for application to an ordi nary piano o1' organ, the key-board of which is represented in dotted lines, A and B being the white and black keys and c the front rail of the case. C and L are longitudinal strips, and K a parallel rod of a frame constructed so as to be applied to the key-board; and to the strip C' are hung levers E, which project one over each key, the levers above the black keys bearing directly on the latter, and the others lijaving at the lower sides projections D,which bear upon the white'keys, so that the levers are all parallel, the bearing-points being covered by felt pads.` Upon the rod K slides a strip, F', carrying a series of keys, A' B', arp ranged, as respects each other, in precisely the same manner, and having the same movements, as those of the key-board, the white keys A' resting at their front ends on projections D3 on the levers E, and the black keys B' upon projections D2 of said levers.

The strip F' may be moved upon the rod K so as to bring the upper keys directly over the corresponding keys of the lower board, in which case a piece of music played upon the upper keys, which operate, through the levers E, upon the lower ones, will be produced in the same key and with the same effect as it' played directly upon the lower key-board.

When, however, it is desired to transpose or play the piece upon a key that is higher or lower than that in which the music is written, the sliding keyboard is moved to the right or left the Width of one or more keys, according as the new scale is one or more half-tones higher or lower than that from which the piece is to be transposed, when, upon playing the piece, as written, upon the upper key-board, the effect will be, upon depressing each upper key, to produce a sound that is one or more half-tones higher or lower than that produced by a key in the same position upon a permanent board, thus transposing the entire piece without any other effort upon the partof the player than is required to produce the piece in the key in which it is Written.

I claim- The combination, in a transposin g key-board, of levers E,vhavin g projections D2 D3, and keys A' B', adjustable above the levers and resting on said projections, as set forth.

In testimony whereof I have signed my name to this specification in the presence ot two subscribing witnesses.

AUGUSTE DSIR BERNARD WOLFF.

Witnesses:

EDMoND TI-I1BAULT,J1-., EMILE RICHARD. 

